Tag: "sperm" at biology news
Enticed By A Chemical Tease, Female Beetles Are Rewarded With A Nuptial Gift To Protect The Next Generation
...nsferred to the female beetle in the mating male's sperm
package. And she, in turn, bestows the chemical on her eggs, which are protected by the chemical from predators. Without the chemical, fire-colored beetle eggs would be lunch for other insects. "Protecting the eggs is clearly to the advantage of bo...
Hawaiian Whales Show 'No Overt Response' To Sounds Of ATOC Simulation
... commented. "Unfortunately, you can't just call a sperm
whale into the lab, put on a set of earphones and give it a hearing test. So we're proceeding very cautiously." ATOC-Marine Mammal Research Program scientists began gathering "baseline" data on whale behavior and distributions off the north shor...
Prostate Cancer May Be Predicted 10 Years Before Diagnosis
...iquefy the seminal fluid after ejaculation so that sperm
can swim freely. Some PSA leaks into the blood stream from prostatic cells, more so when the prostate enlarges. Part of the PSA binds to alpha-1 antichymotrypsin (ACT), a protein that prevents PSA from destroying cells by deactivating enzymatic fun...
Prostate Cancer's Aggressiveness May Be Predicted Early By The Ratio Of Free To Total PSA
...iquefy the seminal fluid after ejaculation so that sperm
can swim freely. Some PSA leaks into the blood stream from prostatic cells, more so in the presence of prostate disease such as infection, enlargement called benign prostatic hyperplasia (BPH) or cancer. Part of the PSA binds proteins in the blood an...
A New Biochemical Link Established Between Stress, Sex And Dominance
...ve the fully developed gonads capable of producing sperm
to fertilize those eggs. All in the head All of this is reflected in a patch of cells in the fish's brain that increase eight-fold in volume while they pump out big doses of gonadotropin releasing hormone (GnRH), the coordinator of sexual developme...
Study Shows Hereditary Legacy Of Radiation Exposure
... conception, corresponding to a sensitive stage in sperm
development.These grandchildren mice also weigh less than normal mice and their spermare less efficient at fertilization. Wiley suspects her fairly simple, yet exquisitely sensitive, cellularassay could be used to predict inherited effects of radiat...
Stress Lowers Sperm Count By Overwhelming Cells That Make Testosterone
NEW YORK - Why does stress cause a man's sperm
count to plummet? Research led byPopulation Counci...testes producetestosterone, which is necessary for sperm
formation. Offering the first evidence that stress acts locally within the testes, via theLeydig cel...
Reanalysis Of International Data Finds Sharp Decline In Sperm Density
...searchers have concluded that a decline in average sperm
densityreported in the U.S. and other Western coun...exhibited an average annual decrease of 1.5million sperm
per milliliter of collected sample, or about 1.5 percent per year,while those in European countries ...
At Life's Most Sensitive Stage, Embryos Cope With Stress
...ggs todemonstrate how a successful meeting between sperm
and egg triggers the egg tobecome an embryo. To wr... depend on the vagaries of current and tide to get sperm
and egg togetherclose enough for fertilization to begin. Previous studies assumed that these organis...
Biotech Approach To Feral Cat Problem Devised
... which recognize the ZP and block the ability of a sperm
to fertilize the egg. While many people recognize...P surrounding the egg, they inhibit the binding of sperm
and thus block fertilization. Scientists have looked at various techniques for delivering oral rabi...
Poetically Timed With Spring, Budding Yeast Yield Possible Insight Into Male Fertility--And Infertility
...tely pave the way for an understanding of whyhuman sperm
sometimes doesn't fully develop, causing sterility...e. Men with the infertility syndrome haveimmature sperm
that are developmentally interrupted at the same stage ofcreation as was observed in defective yeast...
The First Rejection: Eggs Sequester Bits Of Sperm For Later Elimination
...reviously noticed that the long tails of fruit fly sperm
entered the egg during fertilization, undermining the idea that the only role of the sperm
tail is to propel its genetic cargo to the egg. "It was remarkable that the egg accepted so much sp...
UB Fertility Researchers Find They Can Predict Pregnancy By Assessing Two Sperm Abnormalities
...ic clinical pregnancies and very low levels of two sperm
abnormalities. The two abnormalities -- prema... acrosome is a enzyme-filled cap covering half the sperm
head. Just before fertilization, enzymes from the acrosome, activated at the proper time, soften th...
Monogamy Has Its Rewards For Flies
... for availablefemales. To try to ensure that their sperm
fertilises the female's eggs, maleshave evolved toxic seminal fluid that disables the sperm
of other males thathave mated with the same female, and carries hormones that make the female lessse...
Russian Queens Bee-Little Mites' Impact
...S. hives. The queens, which mate only once, carry sperm
from descendants of Primorski-hatched bees. By next spring, Rinderer's team plans to begin distributing mated Russian queens to beekeepers for experiments to evaluate how well they pollinate plants and produce honey under field conditions. The R...
New Research On Environmental Pollutants
...ry slowly. Thepresence of brominated substances in sperm
whales, which seek food at greatdepths, indicates that these pollutants are found at several hundred metersdepth in the Atlantic. Polybrominated Biphenyls And Diphenylethers In Sperm Whales And Other MarineMammals- A New Threat To Ocean Life? Jacob ...
Duke Study Helps Explain How Cells Divvy Up Genes During Reproduction
...l during a special type of cell division thatmakes sperm
and eggs. When this machinery malfunctions, chromosomes, thecarriers of genetic material, can become jumbled and the wrong number ofchromosomes can end up in each egg. This can result in infertility or syndromessuch as Down's, in which a child has an...
Research Team Finds Gene Causing Two Types Of Muscular Dystrophy
...found in the roundworm c. elegans causesdefects in sperm
when mutated. Brown notes that developing a mouse model with adefective dysferlin gene will help researchers on his team and elsewhere betterunderstand the protein's function and develop strategies to treat these muscledisorders. The research team ...
New Study Highlights Hazards On Hormone Disrupting Chemicals
...programme", headded. New findings showing reduced sperm
quality and increased cancer incidence inhumans has sparkedoff the recent debate. However, there is no Swedish investigation into this, andthe trends from themost comparable countries are highly different. Testicular cancer and prostate cancer in me...
Sperm Protein May Hold Clues For Fertility And Contraceptives
A protein found on the surface of the sperm
of all mammals appears crucial forthe union of the sperm
and egg, as well as for movement of the sperm
into theanimal's oviduct, announce researchers at the ...
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